Copyright (c) 2000, 2013 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
       Andy Clement - Contributions for
                         Bug 383624 - [1.8][compiler] Revive code generation support for type annotations (from Olivier's work)
       Jesper Steen Moeller - Contribution for
                         Bug 406973 - [compiler] Parse MethodParameters attribute
/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *        Andy Clement - Contributions for
 *                          Bug 383624 - [1.8][compiler] Revive code generation support for type annotations (from Olivier's work)
 *        Jesper Steen Moeller - Contribution for
 *                          Bug 406973 - [compiler] Parse MethodParameters attribute
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import org.eclipse.jdt.core.util.ClassFormatException;
import org.eclipse.jdt.core.util.IAttributeNamesConstants;
import org.eclipse.jdt.core.util.IClassFileAttribute;
import org.eclipse.jdt.core.util.IClassFileReader;
import org.eclipse.jdt.core.util.ICodeAttribute;
import org.eclipse.jdt.core.util.IConstantPool;
import org.eclipse.jdt.core.util.IConstantPoolConstant;
import org.eclipse.jdt.core.util.IConstantPoolEntry;
import org.eclipse.jdt.core.util.IExceptionAttribute;
import org.eclipse.jdt.core.util.IMethodInfo;
import org.eclipse.jdt.core.util.IModifierConstants;

Default implementation of IMethodInfo.
/**
 * Default implementation of IMethodInfo.
 */
public class MethodInfo extends ClassFileStruct implements IMethodInfo {
	private int accessFlags;
	private int attributeBytes;
	private IClassFileAttribute[] attributes;
	private int attributesCount;
	private ICodeAttribute codeAttribute;
	private char[] descriptor;
	private int descriptorIndex;
	private IExceptionAttribute exceptionAttribute;
	private boolean isDeprecated;
	private boolean isSynthetic;
	private char[] name;
	private int nameIndex;

	
Params:
classFileBytes – byte[]
constantPool – IConstantPool
offset – int
decodingFlags – int/**
	 * @param classFileBytes byte[]
	 * @param constantPool IConstantPool
	 * @param offset int
	 * @param decodingFlags int
	 */
	public MethodInfo(byte classFileBytes[], IConstantPool constantPool, int offset, int decodingFlags)
		throws ClassFormatException {

		boolean no_code_attribute = (decodingFlags & IClassFileReader.METHOD_BODIES) == 0;
		final int flags = u2At(classFileBytes, 0, offset);
		this.accessFlags = flags;
		if ((flags & IModifierConstants.ACC_SYNTHETIC) != 0) {
			this.isSynthetic = true;
		}

		this.nameIndex = u2At(classFileBytes, 2, offset);
		IConstantPoolEntry constantPoolEntry = constantPool.decodeEntry(this.nameIndex);
		if (constantPoolEntry.getKind() != IConstantPoolConstant.CONSTANT_Utf8) {
			throw new ClassFormatException(ClassFormatException.INVALID_CONSTANT_POOL_ENTRY);
		}
		this.name = constantPoolEntry.getUtf8Value();

		this.descriptorIndex = u2At(classFileBytes, 4, offset);
		constantPoolEntry = constantPool.decodeEntry(this.descriptorIndex);
		if (constantPoolEntry.getKind() != IConstantPoolConstant.CONSTANT_Utf8) {
			throw new ClassFormatException(ClassFormatException.INVALID_CONSTANT_POOL_ENTRY);
		}
		this.descriptor = constantPoolEntry.getUtf8Value();

		this.attributesCount = u2At(classFileBytes, 6, offset);
		this.attributes = ClassFileAttribute.NO_ATTRIBUTES;
		if (this.attributesCount != 0) {
			if (no_code_attribute && !isAbstract() && !isNative()) {
				if (this.attributesCount != 1) {
					this.attributes = new IClassFileAttribute[this.attributesCount - 1];
				}
			} else {
				this.attributes = new IClassFileAttribute[this.attributesCount];
			}
		}
		int attributesIndex = 0;
		int readOffset = 8;
		for (int i = 0; i < this.attributesCount; i++) {
			constantPoolEntry = constantPool.decodeEntry(u2At(classFileBytes, readOffset, offset));
			if (constantPoolEntry.getKind() != IConstantPoolConstant.CONSTANT_Utf8) {
				throw new ClassFormatException(ClassFormatException.INVALID_CONSTANT_POOL_ENTRY);
			}
			char[] attributeName = constantPoolEntry.getUtf8Value();
			if (equals(attributeName, IAttributeNamesConstants.DEPRECATED)) {
				this.isDeprecated = true;
				this.attributes[attributesIndex++] = new ClassFileAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.SYNTHETIC)) {
				this.isSynthetic = true;
				this.attributes[attributesIndex++] = new ClassFileAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.CODE)) {
				if (!no_code_attribute) {
					this.codeAttribute = new CodeAttribute(classFileBytes, constantPool, offset + readOffset);
					this.attributes[attributesIndex++] = this.codeAttribute;
				}
			} else if (equals(attributeName, IAttributeNamesConstants.EXCEPTIONS)) {
				this.exceptionAttribute = new ExceptionAttribute(classFileBytes, constantPool, offset + readOffset);
				this.attributes[attributesIndex++] = this.exceptionAttribute;
			} else if (equals(attributeName, IAttributeNamesConstants.SIGNATURE)) {
				this.attributes[attributesIndex++] = new SignatureAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_VISIBLE_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeVisibleAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_INVISIBLE_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeInvisibleAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeVisibleParameterAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeInvisibleParameterAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.ANNOTATION_DEFAULT)) {
				this.attributes[attributesIndex++] = new AnnotationDefaultAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeVisibleTypeAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS)) {
				this.attributes[attributesIndex++] = new RuntimeInvisibleTypeAnnotationsAttribute(classFileBytes, constantPool, offset + readOffset);
			} else if (equals(attributeName, IAttributeNamesConstants.METHOD_PARAMETERS)) {
				this.attributes[attributesIndex++] = new MethodParametersAttribute(classFileBytes, constantPool, offset + readOffset);
			} else {
				this.attributes[attributesIndex++] = new ClassFileAttribute(classFileBytes, constantPool, offset + readOffset);
			}
			readOffset += (6 + u4At(classFileBytes, readOffset + 2, offset));
		}
		this.attributeBytes = readOffset;
	}
	
See Also:
getAccessFlags.getAccessFlags()/**
	 * @see IMethodInfo#getAccessFlags()
	 */
	@Override
	public int getAccessFlags() {
		return this.accessFlags;
	}

	
See Also:
getAttributeCount.getAttributeCount()/**
	 * @see IMethodInfo#getAttributeCount()
	 */
	@Override
	public int getAttributeCount() {
		return this.attributesCount;
	}
	
See Also:
getAttributes.getAttributes()/**
	 * @see IMethodInfo#getAttributes()
	 */
	@Override
	public IClassFileAttribute[] getAttributes() {
		return this.attributes;
	}

	
See Also:
getCodeAttribute.getCodeAttribute()/**
	 * @see IMethodInfo#getCodeAttribute()
	 */
	@Override
	public ICodeAttribute getCodeAttribute() {
		return this.codeAttribute;
	}

	
See Also:
getDescriptor.getDescriptor()/**
	 * @see IMethodInfo#getDescriptor()
	 */
	@Override
	public char[] getDescriptor() {
		return this.descriptor;
	}

	
See Also:
getDescriptorIndex.getDescriptorIndex()/**
	 * @see IMethodInfo#getDescriptorIndex()
	 */
	@Override
	public int getDescriptorIndex() {
		return this.descriptorIndex;
	}

	
See Also:
getExceptionAttribute.getExceptionAttribute()/**
	 * @see IMethodInfo#getExceptionAttribute()
	 */
	@Override
	public IExceptionAttribute getExceptionAttribute() {
		return this.exceptionAttribute;
	}

	
See Also:
getName.getName()/**
	 * @see IMethodInfo#getName()
	 */
	@Override
	public char[] getName() {
		return this.name;
	}

	
See Also:
getNameIndex.getNameIndex()/**
	 * @see IMethodInfo#getNameIndex()
	 */
	@Override
	public int getNameIndex() {
		return this.nameIndex;
	}

	private boolean isAbstract() {
		return (this.accessFlags & IModifierConstants.ACC_ABSTRACT) != 0;
	}

	
See Also:
isClinit.isClinit()/**
	 * @see IMethodInfo#isClinit()
	 */
	@Override
	public boolean isClinit() {
		return this.name[0] == '<' && this.name.length == 8; // Can only match <clinit>
	}

	
See Also:
isConstructor.isConstructor()/**
	 * @see IMethodInfo#isConstructor()
	 */
	@Override
	public boolean isConstructor() {
		return this.name[0] == '<' && this.name.length == 6; // Can only match <init>
	}

	
See Also:
isDeprecated.isDeprecated()/**
	 * @see IMethodInfo#isDeprecated()
	 */
	@Override
	public boolean isDeprecated() {
		return this.isDeprecated;
	}

	private boolean isNative() {
		return (this.accessFlags & IModifierConstants.ACC_NATIVE) != 0;
	}

	
See Also:
isSynthetic.isSynthetic()/**
	 * @see IMethodInfo#isSynthetic()
	 */
	@Override
	public boolean isSynthetic() {
		return this.isSynthetic;
	}

	int sizeInBytes() {
		return this.attributeBytes;
	}
}